A possibility that Hodgkin's Disease may spread antegrade via the thoracic duct from hepatic paraaortic nodes to supraclavicular nodes forms the basis for this study in experimental animals. To determine whether hepatic macrophages labeled in vivo with radiopaque particles of tantalum can be stimulated to circulate along this pathway, trypan blue will be administered via the portal vein. Lymphatic circulation of labeled macrophages altered by this dye will then be examined by radiographic and histologic technics.